Session: 653. Myeloma/Amyloidosis: Therapy, excluding Transplantation: Poster III
Hematology Disease Topics & Pathways:
multiple myeloma, therapy sequence, Diseases, Therapies, Combinations, Plasma Cell Disorders, Lymphoid Malignancies, Clinically relevant
METHODS: A retrospective cohort of RRMM pts initiating IRd, KRd, or VRd in line of therapy (LOT) ≥2 were followed between 7/2007-9/2018 in Optum’s deidentified national electronic health records database. RRMM pts were defined as those initiating LOT ≥2 between 1/2014 and 9/2018 and were categorized as having or not having prior exposure to R (R-exposed; no-prior-R) in any prior LOT. Index regimen was the first use of I-/K-/or V-Rd. LOTs were defined via an algorithm developed with MM specialists to proxy the definition of a LOT in RCTs & in accordance with NCCN MM Guidelines.6 Baseline data included: CRAB (hyperCalcemia, Renal insufficiency, Anemia, and Bone lesions); high risk cytogenetics (defined as del[17p], 1q21 gain, t[4;14], or t[14;16]); Charlson Comorbidity Index (CCI) score; and modified frailty score using age and CCI score. Median duration of therapy (DOT) and time-to-next-treatment (TTNT) (a proxy for PFS; defined as time from index regimen start to subsequent LOT or death) were estimated using Kaplan-Meier methods and compared using covariate-adjusted Cox proportional hazard models (FIGURE). Observations were censored at time of loss to follow-up (f/u)/end of study period (9/30/2018).
RESULTS: Of 650 pts included, 397 were R-exposed (IRd, n=112; KRd, n=115; VRd, n=170); 253 had no-prior-R (IRd, n=29; KRd, n=62; VRd, n=162). R-exposed pts, overall, were treated in later LOTs (LOT2: 55% v 78%) and had a longer median time from diagnosis to index LOT (26.7 v 13.4 months) than no-prior-R pts; this differed between treatment cohorts (TABLE). In R-exposed pts, more pts with symptomatic relapse (≥1 CRAB symptom, 87%) or high-risk cytogenetics (30%) received KRd than IRd (75% & 23%) or VRd (74% & 16%) (TABLE). More pts treated with IRd were ≥75 years old: 42% (IRd) v 36% (VRd) / 21% (KRd). In R-exposed pts, 35.3% of those receiving VRd in LOT ≥2 had prior V-IMID-based and 53.5% had IMID-based therapy (ie, IMID with no PI nor monoclonal antibody) in LOT1; >98% of LOT1 IMID use was R, across groups. In R-exposed pts, 56.5% of those receiving KRd had prior V-IMID-based and 16.5% had IMID-based therapy in LOT1; in IRd pts in LOT ≥2, 29.5% and 43.8% had prior V-IMID-based and IMID-based therapy in LOT1. In unadjusted analysis, at a median f/u of 11, 11.9, and 14.8 months for I-, K-, and V-Rd, median TTNT for R-exposed pts: 12.3 months (IRd), 7.8 months (KRd), and 13.9 months (VRd) (P=0.50); HRs for TTNTLOT stratified: 0.84 (IRd v KRd), 0.96 (IRd v VRd), 1.15 (KRd v VRd), and median regimen DOTs: 8.4 months (IRd), 7.5 months (KRd), and 9.5 months (VRd) (P=0.75). In no-prior-R pts, HRs for TTNTLOT stratified were significant for IRd v KRd (HR=0.33) and KRd v VRd (HR=1.62) (P<0.01, both); IRd v VRd (HR=0.53; P=0.11). In adjusted analysis, there were no significant differences for R-exposed pts by PI-Rd regimens for TTNT (FIGURE), nor for regimen DOT. For no-prior-R pts, adjusted HR for TTNT was significant for I- v K-Rd (HR=0.36; P=0.03) and for regimen DOT was significant for I- v V-Rd (HR=0.34; P=0.03).
CONCLUSIONS: In this real-world study, the majority of pts received a PI-Rd combination after prior VRd or Rd in front-line. After controlling for baseline characteristics, including prior PI-exposure, PI-Rd triplets were comparable in TTNT in R-exposed pts treated in LOTs ≥2. TTNT was significantly longer for I- v K-Rd in pts with no-prior-R, although this is limited by small sample size. Published studies indicate that individualized treatment recommendations may improve real-world outcomes, such as IRd v KRd in frail pts which was associated with significantly longer TTNT.6 Prior-R exposure, in our analysis, does not appear to influence the relative PI-triplet regimen effectiveness in LOTs ≥2. With increasing use of R in earlier LOTs, understanding real-world treatment patterns and subsequent PI-Rd effectiveness in consequent LOTs is key for optimizing RRMM pt management.
Disclosures: Cherepanov: Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Current Employment. Romanus: Takeda: Current Employment. Raju: Xcenda: Current Employment, Other: Xcenda received research funding from Takeda. Blazer: Xcenda: Current Employment, Other: Xcenda received research funding from Takeda. Farrelly: Xcenda: Current Employment, Other: Xcenda received research funding from Takeda. Stull: Takeda: Current Employment. Ailawadhi: Amgen: Research Funding; Celgene: Honoraria; Oncopeptides: Consultancy; GSK: Consultancy; Takeda: Honoraria; Janssen: Research Funding; Pharmacyclics: Research Funding; Cellectar: Research Funding; BMS: Research Funding; Medimmune: Research Funding; Phosplatin: Research Funding; Beigene: Consultancy.
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